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What coupling caps are better to be avoided in high temperature case..

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I have my BAT VK-5SE with six-pak coupling caps. I think they are Jensen PIO caps. The preamp is pretty hot. In less than 10 years, the caps leak DC current. I need to find caps to replace them. Any suggestion for replacement, or any caps I should be avioded in this high temperature case?

Follow Ups:

RE: What coupling caps are better to be avoided in high temperature case.. - casouza 20:45:27 07/19/10 (4)
The least reliable coupling caps under extreme heat are polystirene and paper in oil. Unfortunately, for piece-of-mind, you need to avoid oil caps, all of them go leaky with time, with one exception: Mundof Silver in Oil, rated for 1200V, excellent sound quality and very good at taking heat.
The most heat-resistant caps are Teflon ones. VH CU TFT are the best currently available, though very expensive.
Mundorf and VH TFT caps will sound way more transparent than your current oil caps. That can be a plus or a minus, depending on your priorities.
good luck

Edits: 07/19/10
- RE: What coupling caps are better to be avoided in high temperature case.. - PeterCapo 11:00:57 12/20/12 (3)
  Interesting post but I am a bit puzzled. You mention that the Mundorf silver/oil is good at handling higher temperatures. But, it seems that the Mundorf website lists the maximum temperature as 55 C (131 F). Do you have information from another source about Mundorf silver/oil temperature tolerance?
  Hope this link works...
  - http://www.mundorf.com/english/bauteile/kondensatoren/mcap-s (Open in New Window)
  Edits: 12/20/12
  - Reports of Mundorf SIO Heat Failure - Maxamillion 13:37:11 12/21/12 (2)
    There have been reports of SIO caps failing in hot amps. According to this link Mundorf themselves say the oil destroys the silver foil in hot environments...
    - http://www.diyaudio.com/forums/tubes-valves/185374-caps-mund (Open in New Window)
    - RE: Reports of Mundorf SIO Heat Failure - PeterCapo 14:49:43 12/21/12 (1)
      Whoa Nellie! Thank you for posting that. You may have just saved me a lot of trouble.
      I wonder if the same can be said for the Jensen PIO???
      Peter
      
      Edits: 12/21/12
      - Jensons are a DEFINITE NO-NO - Maxamillion 17:30:23 12/21/12 (0)
        
        In Reply to: RE: Reports of Mundorf SIO Heat Failure posted by PeterCapo on December 21, 2012 at 14:49:43
        
        I have personally had their copper foil PIOs short completely at high voltage within days of installation, and there are NUMEROUS other reports of them failing in amps. Do a search, you'll find the stories.
        Here's one example of the complaints:
        http://db.audioasylum.com/mhtml/m.html?forum=tubediy&n=21231 (Open in New Window)
        
        Edits: 12/21/12
RE: What coupling caps are better to be avoided in high temperature case.. - FenderLover 04:17:51 07/16/10 (0)
I'm not sure about specific cap types, but the higher the voltage rating... usually the better the heat tolerance. For unavoidable, hot places I try to use 1600VDC rated caps.

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